Unforeseen Consequences of Therapy With Continuous-Flow Pumps

Abstract

> For use almost can change the stamp of nature. > > — Hamlet , Act III, Scene IV Hamlet's statement may well be applied to the marked alteration in normal mammalian physiology introduced by the use of left ventricular assist devices (LVADs), particularly the nonpulsatile devices. This alteration of the “stamp of nature” has led to changes in the normal circulatory physiology not previously encountered in the field of medicine. Two unanticipated consequences of the clinical application of LVAD technology—acquired aortic valve insufficiency (AI) and acquired von Willebrand syndrome (VWS)—are reported in this issue of Circulation: Heart Failure . Articles see pp 668 and 675 The report by Cowger et al1 quantifies a single-center experience with acquired AI after implantation of both the pulsatile HeartMate XVE (HM-XVE) and the nonpulsatile HeartMate II (HM-II) LVAD (Thoratec Corporation, Pleasanton, Calif). These investigators used echocardiography to study 78 patients who received the HeartMate XVE (n=25) or HeartMate II (n=53) LVAD between 2004 and 2008. They performed 315 studies at set time intervals and graded AI and aortic valve opening according to classic echocardiographic methodology. Trends in the development of AI were assessed in the group as a whole and were then compared by device type. Because this was a single-center study, the numbers available for follow-up evaluation were limited (49 patients at 6 months, 29 patients at 12 months, 13 patients at 18 months, and 5 patients at 24 months). However, an increase in both the development and the severity of AI was noted during this period. The grade of moderate-to-severe AI was approximately 11% at 6 months, 26% at 12 months, and 51% at 18 months. Compared with patients with the HM-XVE device, those with the HM-II pump had an increased incidence and severity of AI; however, in no patient was the AI severe enough to require intervention. The authors …